Shelf unit



FIG. 1 is a perspective view of a shelf system showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof, the left sideelevational view being a mirror image thereof;

FIG. 4 is a rear elevational view thereof; and,

FIG. 5 is an enlarged top plan view thereof.

The bottom of the shelves form no part of the claimed design. The brokenlines shown are for illustrative purposes only and form no part of theclaimed design.

The ornamental design for a shelf unit, as shown and described.